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Mirrors > Home > MPE Home > Th. List > fun0 | Structured version Visualization version GIF version |
Description: The empty set is a function. Theorem 10.3 of [Quine] p. 65. (Contributed by NM, 7-Apr-1998.) |
Ref | Expression |
---|---|
fun0 | ⊢ Fun ∅ |
Step | Hyp | Ref | Expression |
---|---|---|---|
1 | 0ss 3924 | . 2 ⊢ ∅ ⊆ {〈∅, ∅〉} | |
2 | 0ex 4718 | . . 3 ⊢ ∅ ∈ V | |
3 | 2, 2 | funsn 5853 | . 2 ⊢ Fun {〈∅, ∅〉} |
4 | funss 5822 | . 2 ⊢ (∅ ⊆ {〈∅, ∅〉} → (Fun {〈∅, ∅〉} → Fun ∅)) | |
5 | 1, 3, 4 | mp2 9 | 1 ⊢ Fun ∅ |
Colors of variables: wff setvar class |
Syntax hints: ⊆ wss 3540 ∅c0 3874 {csn 4125 〈cop 4131 Fun wfun 5798 |
This theorem was proved from axioms: ax-mp 5 ax-1 6 ax-2 7 ax-3 8 ax-gen 1713 ax-4 1728 ax-5 1827 ax-6 1875 ax-7 1922 ax-9 1986 ax-10 2006 ax-11 2021 ax-12 2034 ax-13 2234 ax-ext 2590 ax-sep 4709 ax-nul 4717 ax-pr 4833 |
This theorem depends on definitions: df-bi 196 df-or 384 df-an 385 df-3an 1033 df-tru 1478 df-ex 1696 df-nf 1701 df-sb 1868 df-eu 2462 df-mo 2463 df-clab 2597 df-cleq 2603 df-clel 2606 df-nfc 2740 df-ral 2901 df-rex 2902 df-rab 2905 df-v 3175 df-dif 3543 df-un 3545 df-in 3547 df-ss 3554 df-nul 3875 df-if 4037 df-sn 4126 df-pr 4128 df-op 4132 df-br 4584 df-opab 4644 df-id 4953 df-xp 5044 df-rel 5045 df-cnv 5046 df-co 5047 df-fun 5806 |
This theorem is referenced by: funcnv0 5869 fn0 5924 f10 6081 0fsupp 8180 strlemor0 15795 strle1 15800 lubfun 16803 glbfun 16816 1pthonlem1 26119 1pthdlem1 41302 |
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